Question

11. Out of 24 girls, 6 are 1m 15 cm in height,
8 are 1 m 5 cm and the rest 1 m 11 cm.
What is the average height of the girls?​

Answer 1

Answer:

average height of the girls=1.15+1.5+1.11÷3=3.13

Answer 2

Given :

• Out of 24 girls, 6 are 1m 15 cm in height,8 are 1 m 5 cm and the rest 1 m 11 cm.

Find :

• What is the average height of the girls?

Solution :

• Height of 6 girls : - 1 m 15 cm

Converting in cm →

$:\implies\sf{100 + 15}$

$:\implies\sf{115}$

• Height of 8 girls : - 1m 5 cm

Converting in cm →

$:\implies\sf{100 + 5}$

$:\implies\sf{105}$

• Height of the rest the girls : - 1m 11cm

Converting in cm →

$:\implies\sf{100 + 11}$

$:\implies\sf{111}$

Now,

Total height of 6 girls

$:\implies\sf{6 \times 115}$

$\boxed{\therefore \sf{690}}$

Total height of 8 girls

$:\implies\sf{8 \times 105}$

$\boxed{\therefore \sf{840}}$

Total height of rest of the girls

Rest of girls → 24 - ( 6 + 8 ) = 24 - 14 ⇒ 10 girls

$:\implies\sf{10 \times 111}$

$\boxed{\therefore \sf{1110}}$

Then,

$\sf{For \: Average}\longrightarrow$

$:\implies\sf{ \dfrac{Sum \: of \: observation}{Total \: number \: of \: observations}}$

$:\implies\sf{ \dfrac{690 + 840 + 1110}{24}}$

$:\implies\sf{ \dfrac{2640}{24}}$

$\boxed{\therefore \sf{Average = 110}}$